With the improvements in properties of charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) image sensors, as well as the reduction in size, it requires the corresponding lens assembly to meet demands on high imaging quality and miniaturization.
Although a triplet lens assembly in the related art has been developing relatively mature, it still exist many restrictions. For example, miniaturization leads to a relative narrow filed angle, which may be enlarged by changing a diopter of a lens in the lens assembly at the expense of worsen aberration, thereby results in degradation in the imaging quality.